Watercraft, especially those of the type known as personal watercraft, are commonly powered by internal combustion engines positioned within their hulls. These engines are arranged to drive a water propulsion device for propelling the craft.
As is well known, it is undesirable to allow water to enter the intake system of such an engine, as the water may foul the combustion chamber(s) and cause the engine to stall or stop. In addition, the water may be passed through the engine to a catalyst positioned in the exhaust system, damaging it as well.
It is common for the air intake to be positioned at the top of the engine and may open upwardly. In the watercraft setting, this is undesirable, since water may flow directly into the intake and down into the engine. Thus, as one method for reducing the opportunity for water to enter the intake system, the air intake opening leading to the engine may be positioned within an air box, with air supplied to the air box through an inlet or pipe.
A problem also exists with this arrangement relating to the nature of personal watercraft. This type of watercraft is often capsized, laying on either side or completely upside down. When this occurs, water in the engine compartment or elsewhere may then still enter the air box or air intake to the engine.
An improved air intake arrangement for an engine of the type utilized to power a watercraft is desired.